[HN Gopher] Complex life forms existed 1.5B years earlier than b...
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Complex life forms existed 1.5B years earlier than believed, study
finds
Author : isaacfrond
Score : 87 points
Date : 2024-07-30 10:19 UTC (4 days ago)
(HTM) web link (abcnews.go.com)
(TXT) w3m dump (abcnews.go.com)
| lainga wrote:
| That would be funny! It would mean they emerged right after the
| Huronian icehouse period ended, in the same way the Cambrian
| Explosion happened right after the Cryogenian period ended.
|
| [] https://en.wikipedia.org/wiki/Greenhouse_and_icehouse_Earth
| Qem wrote:
| IIRC this was associated to an early, brief spike in
| atmospheric oxygen. It went up, fell, and then took about one
| gigayear to increase again to large sustained levels closer to
| what we have today. Large organisms have low area to volume
| ratios, and require a high level of oxygen to scale up while
| producing enough energy. See https://ars.els-
| cdn.com/content/image/1-s2.0-S16749871120008...
|
| Source:
| https://www.sciencedirect.com/science/article/pii/S167498711...
| frutiger wrote:
| > while producing enough energy
|
| "while transforming enough energy" is both more accurate but
| also educates the lay reader by hinting at the processes
| involved.
| MattPalmer1086 wrote:
| If true, and complex life evolved more than once on the same
| planet, then it is much less likely as a strong candidate for the
| great filter [1].
|
| So, very roughly, either life is hard to get started at all (but
| life started about as soon as possible on earth), intelligence is
| hard to evolve (although we see many species with intelligent
| behaviour, if not at human level), or it's in our future (that
| intelligent life tends to destroy itself).
|
| [1] https://en.m.wikipedia.org/wiki/Great_Filter
| hansvm wrote:
| Are you using "the great filter" as a shorthand for any
| resolution to the Fermi paradox?
| MattPalmer1086 wrote:
| No, the argument here is specifically about the great filter.
| I know there are other possible resolutions to the Fermi
| paradox, although I haven't found most of them very
| convincing.
| Enginerrrd wrote:
| I mean the most obvious solution to the fermi paradox is
| just that aliens are hard to see. If we put an equivalent
| human civilization even on one of the explanets we've
| identified, we'd never know it. Our signals are simply too
| weak and disorganized, and the switch to digital has made
| them even harder to identify from the background. Planets
| are located right next to huge sources of radio noise:
| stars.
|
| Until we can reliably detect a species like ourselves on
| another planet, it seems very silly to assume they aren't
| there.
|
| The assumptions on detection all kind of assume that aliens
| that are much more advanced will have much more obvious
| signals of emery usage or other detectable signals, but
| I've never been convinced by these assumptions. Energy
| usage is likely a logistic curve rather than an ever
| expanding exponential. There so much room at the bottom for
| greater efficiency. It also seems quite sensible that a
| species either eventually copes with equilibrium or dies
| out due to issues with unchecked growth.
|
| There's SO MUCH energy available here on the earth that we
| could go for millenia of computational/energy growth while
| pursuing more efficient systems. The assumptions that lead
| to conclusions about megastructures are pretty dubious. I
| could go on at length about that, but I will just leave it
| at that.
| MattPalmer1086 wrote:
| It only takes one life form to achieve interstellar
| capability, and they would spread across the galaxy in
| only a few million years. That doesn't seem to have
| occurred (although, maybe it has and as you say, we just
| can't detect them, and they're leaving us alone).
| Enginerrrd wrote:
| Yeah but IMO expansion via "interstellar capability" is
| just not compatible with a civilization.
|
| As our species has developed, the time scales that matter
| to us have shrunk, not grown. I just don't think you can
| have a single coherent civilization work when relativity
| places such stringent limitations on communication speed.
| A super advanced civilization likely evolves and changes
| on much smaller time scales than ours does currently. It
| doesn't seem possible for such a civilization to not
| totally fracture at interstellar scales.
|
| Unless there's physics we don't know about, interstellar
| distances are probably just not really compatible with a
| civilization. So, if one exists, its probably a serious
| rarity within a rarity. i.e. the lack of observable
| existence of such a noticeable civilization does not make
| a good argument against aliens in my opinion.
| MattPalmer1086 wrote:
| It's a good point, but there is no reason to suppose they
| have to be a unified civilization. Just that they can
| spread in the first place and their descendants can do
| the same.
| rowanG077 wrote:
| I'm not so sure I agree. There is nothing stopping a
| species that experiences years as we do minutes. Such a
| species would have no problem with the time scales needed
| for interstellar travel.
| sdenton4 wrote:
| A fun problem with this is that there are 500k minutes in
| a year, so the critical free minutes needed to get into
| orbit quickly would be like working at nanosecond
| scale... Our slow friends would presumably need 100%
| automation to survive just about any kind of launch.
| (Nevermind landing.)
|
| (This also raises for me a fun way to continue Moore's
| law by making lived experience slower...)
| krapp wrote:
| Or maybe any number of things can go wrong within a
| million years that prevents the few species capable of
| interstellar travel from unbounded exponential expansion,
| including but not limited to said species not wanting to
| engage in unbounded exponential expansion.
|
| Mathematicians always seem to assume that reality is as
| simple as a plot on graph paper, but if that were the
| case we would have had hotels on Mars by now.
| card_zero wrote:
| Perhaps there is some obvious direction in which to
| engage in unbounded exponential expansion, more
| attractive than exploring the galaxy - not full of vacuum
| and vast distances and cold rocks. Everybody else is
| exploring _that_ space instead, and we haven 't found it
| yet.
|
| Or, quite reasonably, human-like intelligence is special
| and galactic-scale rare. Do we think every _other_ kind
| of unlikely life exists elsewhere in the galaxy? If there
| are definitely other human-like intelligent life forms in
| the galaxy, then there are even more definitely flying
| pigs with nineteen legs and wheels on the ends. Does it
| feel so intuitively correct, considering that? The
| argument here is "but orangutans ... and crows and
| parrots ... and dolphins ... and octopuses ... and
| elephants ... they all _abound_ with the potential to
| build rockets and electronics and self-replicating space
| probes. Any million years now, any one of those species
| could flip into producing lots of ideas and constructions
| and exploring everywhere. " But, really? Sure, they do
| stuff with sticks and half-coconuts, but is "the
| parrot/octopus/elephant space program is just around the
| corner" really a parsimonious extrapolation from observed
| animal stick-handling?
|
| Besides, nerve cells only evolved once, maybe _that_ was
| a freakish event. Maybe every other animal in the galaxy
| is a sponge.
| SoftTalker wrote:
| I think the simple answer to that is that the distances
| are simply too vast (and they are expanding). FTL is
| impossible and even approaching light speed is not
| economically feasible. That limits any spacefaring beings
| to their local planets, pretty much, and if our solar
| system is at all representative, the majority of the
| planets are uninhabitable.
| MattPalmer1086 wrote:
| We are already planning interstellar probes that appear
| feasible with only modest advances [1].
|
| Imagine what we will be able to do with another 1000, or
| 10000 years of development. Can't see any fundamental
| reason why we could not ultimately build infrastructure
| and print up some lifeforms at their destinations.
|
| [1] https://en.m.wikipedia.org/wiki/Breakthrough_Starshot
| SoftTalker wrote:
| For some definition of "modest"
| refulgentis wrote:
| Orders of magnitude are unusually easy in our industry.
| These are absolutely mindboggling numbers beyond
| comprehension.
|
| You need to move 500K hiroshimas a second for 80 kg (175
| pounds). You'd also need some pretty fast brakes lest you
| run into some pretty small things. You also have a really
| bad recursive problem, at 100% E=MC^2 efficiency, you
| need to turn 100 kg of mass to pure energy, per second,
| to move 80 kg. So actually you need to move 180 kg, which
| requires...etc. etc.
|
| This is the base of this thread, the Fermi Paradox: if it
| was a relatively quick scaling away, where is everybody?
| It's "turtles all the way down" to respond that there is
| no paradox, just imagine us in 10K years, even if we knew
| for 100% certainty we'll be there in 10K years.
|
| Note the wikipedia article you linked uses "concept" 10
| times, the roadshadow was in 2016, and has no updates
| after November 2017, 6.75 years ago.
| marcosdumay wrote:
| We can find life like our own hundreds of ligh-years
| away. And there are plenty of plans for improving this.
|
| Anyway, the Fermi paradox isn't about finding life on
| other planets.
| Qem wrote:
| > If true, and complex life evolved more than once on the same
| planet, then it is much less likely as a strong candidate for
| the great filter [1].
|
| The hard step was not complexification of life. It was long-
| term atmospheric oxygenation. It took two attempts, the first
| one short-lived, and between 3-4 billion years to finally
| succeed for good.
| com wrote:
| It's too early to say whether it is "for good", unless you're
| talking about atmospheric oxygenisation - that one almost
| certainly has an end date!
| MattPalmer1086 wrote:
| On earth... We don't know what other chemistries might be
| viable.
| marcosdumay wrote:
| I vote on abiogenesis.
|
| But yeah, oxygenation is a good candidate. Anyway we don't
| have that much of certainty about how it happened exactly.
| Qem wrote:
| It's not necessary to assume a single hard step to explain
| the rarity of intelligent life. Considerations about the
| late appearance of a technological civilization on Earth
| point to between five and six hard steps from origin of
| life to us. Abiogenesis can account for one, oxygenation
| for another, and we still need to find another three or
| four more. See https://arxiv.org/pdf/0711.1985
| marcosdumay wrote:
| That that paper is one (very good) explanation for the
| early and sudden appearance of life on Earth, despite it
| being presumed a rare phenomenon.
|
| But there are other possible explanations.
|
| About the Great Filter, in principle we can expect the
| probability of those things to vary by several orders of
| magnitude, so only one would qualify. All of them being
| equally unlikely is actually harder to explain than the
| alternative.
| njtransit wrote:
| Or the great filter is a misconception based on an extremely
| myopic view on the universe.
| MattPalmer1086 wrote:
| Well true, the great filter may not be the entire explanation
| for the Fermi paradox. It seems uncontroversial though that
| the probability of each of the steps to get from lifeless to
| intelligent life will be a factor.
| exe34 wrote:
| possibly, but absence of evidence isn't evidence of presence.
| bostonwalker wrote:
| The evolutionary transition from single-celled to multicellular
| life has actually been repeatedly accomplished in vitro [1]. So
| highly unlikely to be a Great Filter.
|
| [1] https://archive.ph/1yCVn
| sigmoid10 wrote:
| The study in the article suggests that these early
| multicellular organisms failed to take hold. So there was
| probably something needed that was missing. And it still took
| billions of years for complex live to emerge, whereas single
| celled life appeared almost immediately once the earth cooled
| down enough to have liquid water. Whether it took two billion
| years or 3.5 doesn't matter so much when you think of it as a
| potential filter.
| api wrote:
| There are so many more possibilities. The entire topic of the
| Fermi paradox is a massive tower of assumptions and hidden
| variables for which we have no information.
|
| We don't even know the paradox is real since we haven't
| explored our own solar system enough to rule out aliens or
| artifacts of their visits in our back yard, nor can we rule out
| advanced observers intentionally not revealing themselves for
| any number of rational reasons. There could be an abandoned
| underground alien base on the Moon and we'd have no clue. We
| have barely gone anywhere.
|
| If we hit, say, the level of development in The Expanse and
| still find nothing (no protomolecule haha) then maybe we can
| say there is definitely a paradox.
|
| There's also the assumption that there is a single discrete big
| and dramatic great filter. That's the Hollywood version. In
| reality there could just be a continuous probability of failure
| due to any number of events whether endogenous or external
| spread across billions of years that amounts to a great filter.
| The probability per day of "biosphere failure" or some other
| condition that dooms a potential spacefaring intelligence
| doesn't need to be high to amount to a probability near 1.0
| over geological time scales.
|
| Let's say given we are sending our probes and capsules we are
| probably at least 50% of the way there. If the cumulative great
| filter were near 1.0 probability of failure this would imply a
| 50/50 probability of our success. Those are of course made up
| round numbers just to illustrate how that would work. We have
| no way to know what the actual numbers are because we have a
| sample size of one.
|
| The whole thing is just speculation until we have more actual
| data.
| MattPalmer1086 wrote:
| Well, the Fermi Paradox is misnamed because it isn't a
| paradox at all. It's just the observation that we don't see
| evidence of other life out there, and wondering why not - for
| which there are lots of possible explanations.
|
| As you say, we don't have enough data to know one way or
| another, but even when we do, there will still be no paradox.
| layer8 wrote:
| The sheer number of stars in the galaxy and the absence of
| evidence of other life are in apparent contradiction --
| hence a paradox. A paradox doesn't necessarily mean a hard
| logical contradiction.
| mr_mitm wrote:
| But this is not even a soft contradiction, or even an
| apparent contradiction. It's a problem with too many
| possible solutions so we don't know which one to pick. A
| paradox appears to have no solutions (until it's solved).
| layer8 wrote:
| Given the number of stars, you would expect evidence of
| other life if life isn't exceedingly rare. But we have no
| particular explanation why it would be exceedingly rare,
| and given the abundance of life on Earth one wouldn't
| expect it. So the fact that we see no evidence runs
| against our expectations. Nonintuitive observations,
| where the observation doesn't provide any explanation,
| already counts as a paradox.
| forgot-im-old wrote:
| It's popular to suggest we don't hear aliens because they all
| destroyed themselves. But a basic RF link budget calculation
| shows that even an Arecibo sized antenna pointed perfectly at
| another Arecibo telescope on an alien planet, and
| listening/transmitting at the exact right times, could only
| barely contact one or two of the nearest stars.
|
| This fact is buried in all the Fermi Paradox discussions
| because Fermi's point was the implications of his work on
| nuclear weapons when he brought up alien contact.
|
| It has since been used to make the case for Reagan's Strategic
| Defense Initiative. Which apparently Elon Musk is now
| continuing... https://ioc.exchange/@muskfiles
| nimish wrote:
| I think people, for both good and bad faith reasons, vastly
| underestimate how unlikely it would be for any sort of
| artificial signal to reach us.
|
| It would need to be so powerful and so precisely aimed at us
| that firing randomly into the void would be pointless. We can
| barely detect the most energetic events in the universe like
| quasars and gamma ray bursts as it is.
|
| And that assumes we could even decode it -- advanced coding
| uses scrambling techniques that deliberately make the signal
| look like noise to the uninformed receiver...
| exe34 wrote:
| presumably nowadays we would only aim at stars with a
| planet with an atmosphere we might at least suspect to be
| influenced by biology (i.e. contains some gas that couldn't
| be formed and maintained by known geological processes). so
| maybe aliens would see oxygen in our atmosphere and aim at
| us - but you'd still have to get the timing right: we might
| have been burning witches the last time one message came by
| and next time we might be in the midst of some other social
| disturbance.
| throw9474 wrote:
| The most interesting discussion on Elon's nuclear weapons
| interception plans was xAI's,
|
| https://www.reddit.com/r/ChatGPT/comments/1dgyujd/comment/l8.
| ..
| dTal wrote:
| The Fermi paradox does not merely concern the lack of alien
| signals - it also notes the peculiarity of the absence of
| alien spacecraft / visitors. The Milky Way is big, but not so
| big that it's impossible to traverse generationally. If
| interstellar spaceflight capable aliens evolved at _any time_
| in the galaxy 's 13 billion year history other than within
| the past, say, few million years - a fraction of a percent of
| the total - then we should expect them to have colonized the
| galaxy by now. There is 0 evidence that this has happened -
| no monoliths on the moon, no Dyson sphere signatures visible
| in our telescopes. Either they're very quiet for some reason,
| or nobody cracked interstellar travel. That's concerning when
| it seems perfectly possible and desirable to do. The Milky
| Way is big, indeed - big enough and old enough that _someone_
| should be here.
| rini17 wrote:
| Is it possible to find their remnants in the genome? Since
| horizontal gene transfers happen other organisms that survived
| carried the information but perhaps it's too scrambled now.
| warvariuc wrote:
| > Complex life forms existed 1.5B years earlier than believed
|
| I think it would be more correct to say "It's now believed that
| complex life forms existed 1.5B years earlier than believed
| earlier"
| samstave wrote:
| Life doesn't emerge from the Universe. The Universe emerges from
| Life.
| dTal wrote:
| Meta: Why are all the comment timestamps in this thread no older
| than 5 hours, when some comments are over a day old? You can
| verify this by looking at some user pages.
| atombender wrote:
| The post may have been automatically put back on the front page
| as part of the second-chance pool:
| https://github.com/minimaxir/hacker-news-
| undocumented/blob/m....
| gary_0 wrote:
| I'm not sure, but things tend to get a bit messed up when
| articles get reposted multiple times and then the moderators
| (namely dang) merge the comment threads into one. So that might
| be the reason.
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